How To Improve Appetite In A Kid?

Hi Dr. Santosh. My son is 14months old and he suddenly showing now interest in eating. Ex: Yesterday he didn't eat anything since morning, didn't take his lunch(we give rice/dal/vegetables mix as a paste).. so finally we had to force feed him. otherwise he is pretty active.. what shall I do? somebody suggested to try pediasure. usually he takes cerelac and similac apart from lunch food I mentioned above
Pls help.